Long-Term Safety and Tolerability of Apremilast Versus Placebo in Psoriatic Arthritis: A Pooled Safety Analysis of Three Phase III, Randomized, Controlled Trials

ObjectivePsoriatic arthritis (PsA) requires long-term treatment, yet safety concerns and monitoring requirements make maintenance a challenge. This analysis of pooled Psoriatic Arthritis Long-term Assessment of Clinical Efficacy (PALACE) 1, 2, and 3 data describes 3-year apremilast safety and tolerability in PsA. MethodsPatients with active PsA were randomized (1:1:1) to placebo, apremilast 30 mg twice daily, or apremilast 20 mg twice daily. Placebo patients were re-randomized to apremilast 30 mg twice daily or 20 mg twice daily at week 16 (early escape) or 24. Double-blind treatment continued to week 52; patients could continue apremilast during an open-label, long-term treatment phase. ResultsIn total, 1493 patients received at least one dose of study medication and were included in the safety population (placebo: n = 495; apremilast 30 mg: n = 497; apremilast 20 mg: n = 501). Among patients receiving apremilast, 53.2% (767/1441) completed 3 years of treatment. Greater rates of adverse events (AEs) were reported with apremilast (61.1%; exposure-adjusted incidence rate [EAIR]/100 patient-years, 265.1) versus placebo (47.5%; EAIR/100 patient-years, 200.7) in the placebo-controlled period. During weeks 0 to <= 52, the most common AEs occurring in apremilast-exposed patients were diarrhea (13.9%; EAIR/100 patient-years, 18.6), nausea (12.3%; EAIR/100 patient-years, 16.0), headache (9.4%; EAIR/100 patient-years, 12.1), upper respiratory tract infection (9.1%; EAIR/100 patient-years, 11.5), and nasopharyngitis (6.2%; EAIR/100 patient-years, 7.7). Most AEs were mild/moderate with apremilast exposure <= 156 weeks. Rates of depression remained low (EAIR/100 patient-years, 1.8). Major adverse cardiac events (EAIR/100 patient-years, 0.5), malignancies (EAIR/100 patient-years, 0.9), and serious opportunistic infections (EAIR/100 patient-years, 0.0) were infrequent over the 3-year exposure period. Discontinuation rates due to AEs were low (<7.5%) across all apremilast-exposure periods. Incidences of clinically meaningful abnormalities in postbaseline laboratory values was low; most values returned to baseline levels with continued treatment and without intervention. ConclusionApremilast demonstrated a favorable safety profile and was well tolerated up to 156 weeks.